Perfluoroalkyl silicon compounds containing sulfur

ABSTRACT

PERFLUOROALKYL SILYL SULFIDES ARE PREPARED BY REACTING RFCH=CH2 WITH HSRSI= IN THE PRESENCE OF A FREE RADICAL GENERATOR SUCH AS ORGANIC PEROXIDES. THE PRODUCTS ARE USEFUL FOR TREATING FABRICS TO RENDER THEM OLEOPHOBIC AND WATER REPELLENT FOR EXAMPLE TRIFLUOROPROPENE IS ADDED TO MERCAPTOPROPLYTRIMETHOXYSILANE TO GIVE     CF3CH2CH2S(CH2)3CIO1.5   THIS CAN BE HYDROLYZEDTO THE SILOXANE.   CF3CH2CH4S(CH2)3SI(OCH3)3

United States Patent 3,794,672 PERFLUOROALKYL SILICON COMPOUNDS CONTAINING SULFUR Yung K. Kim, Midland, Mich., assignor to Dow Corning Corporation, Midland, Mich.

No Drawing. Filed July 5, 1973, Ser. No. 376,509 Int. Cl. C071? 7/08, 7/18 US. Cl. 260-448.2 N 4 Claims ABSTRACT OF THE DISCLOSURE Perfiuoroal kyl silyl sulfides are prepared by reacting R CH=CH with HSRSI-= in the presence of a free radical generator such as organic peroxides. The products are useful for treating fabrics to render them oleophobic and water repellent. For example, trifluoropropene is added to mercaptopropyltrimethoxysilane to give CF CH CH S(CH Si(OCH This can be hydrolyzed to the siloxane SPECIFICATION As can be seen, the compounds of this invention can be silanes or siloxanes and the latter can be either homopolymers or copolymers. Where Y is the R CH CH SR-- group, the organosilicon compounds can be represented by silanes of the formula YSiX Y(CH )SiX or Y(CH SiX and siloxanes of the unit formula YSiO Y(CH )SiO, Y(CH SiO YXSIO, YX SiQ and All of the above compounds whether silanes, homopolymeric siloxanes, or copolymeric siloxanes are characterized by having one Y group attached to each silicon atom. The copolymeric siloxanes contain two or more of the above siloxane units.

This invention also relates to copolymers of the unit formula (CH:|)n R CH CH1SRSQCmO3 H m and siloxane units of the formula A S b in which R R, and X are as above defined, n has a value from 0 to 2, and m has a value from 0 to 2, the sum of n+m being not greater than 2, A is methyl, phenyl or OF CH CH and b is 0 to 3.

These copolymers are characterized by the fact that some silicon atoms have the Y group attached thereto and some do not. Thus, it can be seen that any one or more of the Y containing siloxane units shown above "ice can be copolymerized with any one or more of units such as SiO ASi0 A SiO, and A SiO The siloxanes of this invention can be in the form of fluids, resins, or rubbers. These can be prepared by any of the conventional well-known techniques for making siloxane fluids, resins, or rubbers.

The compositions of this invention are prepared by reacting olefins of the formula R1CH=CH3 with nsnsixmo in the presence of free radical generators such as peroxides such as, benzoyl peroxide or ditertiary butyl peroxide or azobisnitriles such as azobisisobutyro nitrile or radiant energy such as ultraviolet light, X-rays, or gamma rays. Combinations of these methods can be employed if desired. The temperature at which the reaction is carried out is not critical and generally temperatures in the range of from room temperature to C. or above are sufficient.

The siloxanes of this invention can alternatively be prepared by hydrolyzing and cohydrolyzing the corresponding hydrolyzable silanes. This procedure is carried out by the well-known hydrolytic procedures shown in the art.

The olefins R CH=CH are known materials and can be prepared by any convenient method such as the method shown in US. Pat. 3,012,006, Col. 2, the disclosure of which is hereby incorporated by reference.

The starting mercapto silicon compounds can be prepared by any of the methods shown in the art, for example, by the method shown in British Pat. 1,102,251 which sets forth the general reaction NaSI-I;+ClRSi-= or the method shown in the publication Synthesis and Reactions of Sulfur Compounds, by Gornowicz and Speier appearing in Mechanisms of Reactions of Sulfur "Compounds," volume 3, 1968, which involves the addition of mercapto acetic acid to alkenyl silicon compounds. Finally, the mercapto materials can be prepared by the method shown in US. Pat. 3,314,982, which involves the reaction of thiourea with ClRSi": compounds to give the corresponding thiuronium salt and thereafter decomposing said salt to the corresponding mercaptan. Both of the above patents and the above publication are hereby incorporated by reference. In addition, the best method for making chlorosilanes is to react an alkenyl chlorosilane with liquid H 8 under ultraviolet light.

For the purpose of this invention, R, can be any perfluoroal kyl radical of from 1 to 4 carbon atoms such as CF C F C3F7, or C F These radicals can be either linear or branched. R can be any alkylene radical of from 1 to 4 carbon atoms such as methylene, dimethylene, trimethylene, tetramethylene or isobutylene. X can be chlorine or alkoxy l to 3 carbon atoms such as methoxy, ethoxy, propoxy or isopropoxy or O(CH CH O),,R" radicals such as OCH CH OCH OCH CH OCH CH OCH OCH CH OC H and OCH CH OCH CH OC -H The compositions of this invention are useful for treating fabrics to render them water repellent and oleophobic. Those compositions containing the lower perfiuoroalkyl radicals are also useful as extenders for those compositions containing higher perfluoroalkyl radicals. Extenders are often used in fabric treatments in order to cheapen the composition where a very expensive material such as the higher perfiuoroalkyl materials are being employed.

In addition, the compositions of this invention are useful W as lubricants.

The following examples are illustrative only and should not be construed as limiting the invention which is properly delineated in the appended claims. I I

EXAMPLE 1 A mixture of 576 g. of mercaptopropyltrimethoxysilane, 317 g. of CF CH:CH and l3 g. of di-t-butyl peroxide were reacted in a two liter stainless steel pressure reactor while stirring at 120 C. under autogenous pressure for 23 hours. The liquid product was distilled to EXAMPLE 3 When 3,3,3-trifluoropropene-l is reacted with the following silanes under the conditions of Example 1, the following products are obtained.

at 9 mm. and having a refractive index of 1.4158. The 35 molecular weight by vapor pressure osmometry was found to be 294 as compared with the calculated value of 292. The structure of the compound was further established by carbon, hydrogen and sulfur analysis.

When the following mercapto alkyl siloxanes are reacted with 3,3,3-trifluoropropene-1 in accordance with the procedure of Example 1, the following products are obtained.

Siloxane Product: HSCHzSHOSKCHIhh CF1(CHZ)ZSCH2S1(OSl(CH:)3l1

CH): (0 CH1): H S (CH2): d 101 I Sl(CHz)z0 MK 0 F|(CH:)2S (CH2):S1O( S 1(CH3)2O 1:511

(CH1): 1): {HS(CH:)ziOl4S1 (CF1(CH2)2S(CH:)zSlOlaSl CH: CH: (HS (CHzhiOi lCFz(CHz)zS (CHzh iOlc H: H1): 1 QM (HSCHzCHCHzSllzO lCFflCHflzSCHzCHCHgSihO EXAMPLE 2 EXAMPLE 5 A mixture of 100 g. of

.CF CH CH S (CH Si(OCH 3 When the following silanes are hydrolyzed or whydrolyzed according to the method of Example 2, the following siloxanes are obtained.

M01 M01 perpercent Silane mixture of cent Siloxane copolymer oi- 50 CH: 50 (3H3 C F3(CH2)2S (C'HzhKO CH3): C Fa(CH2)z S (CH2): S

50 (CH3) 251(0 CH3): 50 (CH3) 2510 CF3(CH2)2S(CH:)1S1(OCHJ)1 25 CF3(C H2)zS(CHz)aSlO1,5 25 CeHgSKOCHB): 25 cuflsslo s 25 (I311: 25 $11: CFaCHzCHtSKQCHI): CFzCHzCHzSlO 25 (CH3)2S1(OCH3)2 25 (CHahSiO 25 CF3(CH2)2S (CH2)JS1(OCH3)Z 25 CF (CH2)2S (CHzhSlO 25 CsH5(CHa)Sl(OCHa)z 25 CsI'I5(CIl3) SiO 1O (CeHs)zS1(OCH3)z 10 (CsH5)2SiO 40 CHsSiO1,s

4O CHaSl(OCHa)a When C F CH=CH is reacted with the following and the remaining siloxane units being of the formula silanes or siloxanes in accordance with the procedure of a siol l Example 1, the following products are obtained. 2

Bilane Product HSCH:|Si(O CH3); C(FQCHQCHES CHzSKOCHg);

CH; C

H S CH:CHzSi(O CH3): C F9CHICH2 S (011:) a Si( CH (CHa): H3):

HS(CH:)aSiOCHs C4FaOH:CHaS(CH2)aSiOCH;

Siloxane HS(CH;|) Si{OSKCHQzCnH C|F CHnCH:S(CH:)aSi[ OSi(CHa)aCnHs}s HS(CH1)&S10 SiO Si(CHa)a C FnCHgGH|S(CHa)aSi0 S10 Si(OHa)| 3H2 3H2 EH: 1H1 (I? a C That which is claimed is: 1. An organosilicon compound of the formula C4FoC :C 2)a l K aMs in which R, is a perfluoroalkyl radical of 1 to 4 carbon atoms, R is an alkylene radical of 1 to 4 carbon atoms, X is chlorine, acetoxy, allkoxy of 1 to 3 carbon atoms or --O(CH CH O),,R" in which a is 1 or 2 and R is methyl or ethyl, n and m are both 0 to 2, the sum of n-l-m being not greater than 2, A is methyl, phenyl or CF CH CH and b is 0 to 3..

4. The composition of claim 3 in which R, is (3E References Cited UNITED STATES PATENTS 2,719,165 9/1955 Cooper 260-4482 N 2,960,492 11/1960 Morton et a1. 260-448.2 N X 3,532,733 10/ 1970 Lee 260448.8 R

DANIEL E. WYMAN, Primary Examiner P. F. SHAVER, Assistant Examiner U.S. Cl. X.R. 

